Pluto was first discovered in 1930. Until 2006, students were taught that it" was the ninth and smallest planet in the solar system. Smaller than Earth's moon, it is not even as wide as the United States. Pluto is made up almost entirely of rock and ice. It is so far away from Earth that the NASA New Horizons spacecraft took almost 10 years to get very close to it. Pluto's full orbit around the sun lasts almost 250 Earth years! But as small as it is, as cold as it is, as far from the sun as it is, for all those years it was considered the ninth planet of the solar system... until Eris came around." *?Q/ How does the text describe Pluto English language exam Pluto is made up entirely of gas, and it is bigger than Earth's moon. Pluto is made up entirely of ice, and it is bigger than Venus. Pluto is made up entirely of rock and ice, and it is smaller than Earth's moon. Pluto is made up entirely of rock and ice, and it is bigger than Earth's moon.